I need to build a large foam model quickly and cheaply. The model unfortunately had to be built in several pieces that need to be put together. I am using the blue foam from Dow. Does anyone know of an adhesive that wouldn’t eat through the foam, would have some strength to it, and would cure fairly quickly? Any other advice for putting together this model would be appreciated since this is the first time I’ve worked with this foam.
super 77.
a lot of time in classes, we also used Elmers wood glue with a sheet of paper in the middle.
The glue won’t cure without some air, so the paper allows it to set up.
there’s also various types of transfer or double stick tapes… those are very fast.
Tried 77 but it wasn’t strong enough for what I need. My model is about 4 foot by 4 foot. Also tried wood glue, but it didn’t cure. Will try the paper trick!
…Whaaat!?
the 3M Super 77 Spray adhesive is what we are talking about? It was fine for holding it together while I was cutting it but wasn’t that permanet of a seal. I could take pieces apart and put them back together like moving a post-it note around. I take it that shouldn’t happen then? Did I not use enough?
well, it’s a lot like rubber cement. If you spray both sides, let them dry and put them together, that should give you a more perminent bond.
If that doesn’t work, there’s super 90, but I’m not sure if it’ll eat the foam, try a test piece if you want to use this.
Is it urithane foam? If it is you can use superglue… you can find it in hobby shops (model cars, airplanes, etc…) you can also get a kicker, which speeds up bonding process.
Could you specify what type of foam it is… blue just doesn’t cut it for me.
Hope this helps.
OK, I just checked I don’t think superglue will be good for it it will melt it.
If Super 77 is not good, go to car upholstery shop and get a can or two of the glue they use for headliners for car. It sprays out in spiderweb fashon. Spray, wait until it gets tacky and put both pieces together. It’s a bit messy though.
OF COURSE TEST IT FIRST ON SCRAPS<<<
Good luck.
Blue DOW foam is polystyrene…it also comes in pink in some parts of the US
JWK and VALDO have both suggested the best method:
Spray both sides, let them dry a bit, then put them together. That will hold as tight a bond as anything else…you shouldn’t have a problem if you do it correctly.
Great-Stuff 
a couple of hot glue gun’s is my normal weapon of choice.
Thanks for all your suggestions. The directions say to make the bond while it was “aggresively tacky” which I did not realized would take a few minutes. It did bond much nicer after I waited.
My wood glue finally cured though so it’ll be knowledge for next time.
Thanks again!
Stick with the 77 (properly applied).
When its time to sand the model wood glue becomes a real problem because its much harder than the foam. It will leave a visible line that can be a pain to get rid of.
Hope its not too late.
Try 3m 90 spary adhesive.
the stuff is stronger than super 77
contact cement applied to both sides with a sponge applicator, allowed to dry on both sides, then pressed together.
bonds completely,
leaves no hard ridge between panels, other than the skins of the panels themselves,
no seams, even application,
no overspray, contaminating the area,
but does have some fumes so use in well-ventilated area.
inexpensive, you can bond many many pieces of large surface area for only a few dollars, and fresh applicators are only a few cents each.
How many fuckn replys do ya need…?
There are adhesives available specifically for foam, do some research and look in to it to find a supplier in your local area.
Often I use 24 hour epoxy if time aint an issue, not hard to find. It’s often the heat produced by products that eats in to the foam, not the chemical nature of the adhesive itself. The 24 hr goes off so slowly that it wont effect it.
Hope this helps mate
I use water-based contact cement (specific brand is LePage, I think). There are no organic solvents, so there’s no chance of it eating the foam, and it’s much less toxic (can says non-toxic, but I dunno…I wouldn’t eat it) than the petroleum-based stuff.
You have to let the cement dry fully on both surfaces (it turns pale yellow clear) then press it together. Once the surfaces touch they’re not going anywhere. As a bonus, the stuff will glue almost anything you’re likely to use in the shops – wood, paper, carboard, PS foam, styrene sheet, you name it. There are better glues of other tasks but it’s a good all-purpose stuff.
Spray adhesive – I have to agree with deez on this. If you think it’s too weak, you need to read the directions. It sticks like hell to absolutely everything. I quit using it because it’s too expensive and messy.
Other comments:
Don’t use cyanoacrylate superglue, because it slowly dissolves the foam. Cheaper brands don’t seem to affect it, industrial kinds (read: the only kind worth getting) do. YMMV.
Methylene chloride (used to bond styrene sheet) eats EPS like Alien blood eats spaceships…bubbling and fizzing its way through in a few seconds. Don’t even think about it.
Epoxy will be much, much stronger than the actual foam, so don’t bother.
White glue is slow to dry but it does work. I find it’s best for sealing cracks in an emergency; put some over the crack and smooth it out, and it dries in about 3 minutes. The surface will be rough and it’s hard to sand, but it’s better than having a chunk fall off during your presentation.
WHAT HE SAID
2 COAT RUBBER CEMENT. JUST MAKE SURE TO LET BOTH SIDES DRY BEFORE PUTTING THEM TOGETHER
i can’t believe someone actually said use epoxy, while that would be the most messy, expensive, and altogether impractical adhesive. what you want is quick, easy to apply, and cheap. the best i’ve found is a heavy duty spray from a company in minneapolis called rochford (rochfordsupply.com). tip: drill a hole in both ends of your foam piece in the same location for each piece, then run a dowel of same dia. to align all the pieces.
Cant beleive it? Why not? Without knowing exactly what the job is, it would seem to satisfy the requirements as stated.
My area of work is automotive (ie clay armatures and bucks), so when the model is described as large I’m thinking of things car size … I find most contact adhesives are difficult to apply to both sides of large peices of foam without areas becoming dry or staying overly wet when pressed together. The big plus of epoxy is its strength which was one of the requirements, I’d trust epoxy over a contact adhesive any day. Also there is plenty of time to get the model positioned correctly when bonding without using locators. Another benefit is only small amounts are required to glue to peices together, a few dabs on a large surface will suffice - very easy to apply, small amounts of epoxy can be purchased relatively cheaply too. The only down side is its curing time, overcome by doing it last thing in the day and its ready to go first thing next day. As for messy…depends on who is doing the work, eh?
Haven’t read most of the replies here, but if 77 isn’t working…go to the local Hobby Shop…over here we have Michael’s or Ace Hardware…Sometimes you’ll find stuff…that you never thought about…sometimes…going out yourself to the store…youll find your answer…trial and error is the best advice…